1. Field of the Invention
This invention relates to telephone systems providing directory assistance or similar tvpes of information to subscribers. More particularly. this invention relates to automatic directory-assistance systems.
2. Description of the Prior Art
The principal telephone system in the United States provides for directory assistance through the use of special dialing codes which bring an operator on the line. For example, to obtain long distance information, one would enter the area code (e.g. 617), followed by 555 -1212. The operator typically responds by asking "which city". Upon satisfactory response to that query, the operator asks for the name of the party whose telephone number is sought. In certain areas today, the operator then activates some type of equipment which presents to the operator a display which lists the name or names most closely fitting the information given to the operator by the caller. Upon identifying the desired party's number, the operator will either continue by speaking the telephone number, or by activating a voice-response device which generates spoken words electronically identifying the telephone number.
Various kinds of equipment have been proposed for assisting in carrying out the directory assistance function such as described above. For example, U.S. Pat. No. 4,341,929 (Alexander et al) discloses a data retrieval system for use in telephone directory searching and which employs a data entry unit having individual keys for all of the alphabetic and numeric characters. However, such prior art directory assistance systems suffer from the disadvantage of requiring human (operator) action in responding to a request for assistance.